Structure Of Extradosed Cable-stayed Bridge In Mountainous Area

The restriction of the topographical,geological conditions,the construction of highgrade highway in mountainous area,route design of linear constrained is bigger,inevitably appear curve of long-span Bridges.At present,the mountainous area many long-span curve bridge of continuous rigid frame and continuous beam.As a new type of bridge in recent years,extradosed cable-stayed bridge developed from normal cable-stayed bridge,and the characteristics of this new structure is between the continuous beam bridge and cable-stayed bridge.it has both the advantages ofthe continuous beam bridge and the cable-stayed bridge,the torque to make full use of stay-cables resistance structure,thus than continuous rigid-framed through a curve beam to resist method is more effective and economic,has obvious advantage on the construction of long-span Bridges in the mountains,so the extradosed cable-stayed bridge is of great engineering application value.Based on the statistical analysis of structural forms and structural parameters of the built extradosed cable-stayed bridges,this paper draws design ranges of structure parameters and some other rules.By analyzing and discussing the cable-beam load ratio of extradosed cable-stayed bridge and modifying it,the formula of cable-beam load ratio of curved extradosed cable-stayed bridge was put forward in this paper.Combined with practical work of Longjing River Bridge,the analysis model of curved extradosed cable-stayed bridge was built by the use of finite element software of MIDAS.Then the analysis was focused on the effects of structural behavior in relation to the five structural parameters of Longjing River Bridge,which include flexural rigidity of girder,magnitude of prestressed tendons,crosssectional area of cable,rigidity and height of tower,and then the corresponding rules were concluded finally.Meanwhile,the sensitive structural parameters of girder,tower,cable and pier were obtained by comparing and analyzing the sensitivities of above-mentioned five structural parameters.